Experimental Research Of Mechanical Properties And Thermal Insulation Performance For The Fiber Reinforced Lightweight Aggregate Concrete

Lightweight aggregate concrete has the advantages of light weight,good fire resistance,good seismic performance,good thermal insulation effect and so on,Which has widely used in civil engineering and other engineering.However,the brittleness of lightweight aggregate concrete is relatively large,it is easy to crack and brittle failure,which has restricted its application in practical engineering.The study found that adding appropriate amount of fiber can improve the mechanical properties of lightweight aggregate concrete,which can improve the tensile and flexural properties,preventing the expansion of cracks and change the failure mode.This article through single basalt fiber and polypropylene fiber on different dosage of fiber reinforced lightweight aggregate concrete block for mechanical properties,apparent density and thermal insulation performance test,determined the optimal dosage,and energy saving design.The two factors of basalt fiber and polypropylene fiber were used as experimental parameters,Basalt fiber content of Okg/m3,lkg/m3,2kg/m3,3kg/m3,polypropylene fiber content of Okg/m3,0.3kg/m3,0.6kg/m3,0.9kg/m3?The basic mechanical performance test design a total of 7 sets of experiments of lightweight aggregate concrete with different fiber content under the compressive strength,splitting tensile strength,flexural strength,also made of lightweight aggregate concrete dry apparent density test and thermal performance test.Compressive strength test showed that:under the condition of single basalt fiber,the compressive strength of lightweight aggregate concrete was the largest when the content of basalt fiber was 3kg/m3;In the single polypropylene fiber,in addition to adding amount of polypropylene fiber 0.3kg/m3 the compressive strength of lightweight aggregate concrete is increased by 3.3%,the other two content of lightweight aggregate concrete compressive strength decreased in different degree.Polypropylene fiber and basalt fiber can reduce the number of cracks in the specimen,and the failure of the polypropylene fiber and the basalt fiber show a plastic failure state.The splitting tensile strength test shows that the tensile strength of lightweight aggregate concrete is better than that of basalt fiber and polypropylene fiber.Single basalt fiber,the lightweight aggregate concrete splitting tensile strength enhancement effect reached above 30%,which in the basalt fiber content is lkg/m3,the lightweight aggregate concrete splitting tensile strength is the highest growth rate was 35%,and the splitting tensile strength is enhanced by 33.9%at the dosage of 3kg/m3.Adding polypropylene fiber,to improve the lightweight aggregate concrete splitting tensile strength has obvious effect,the dosage of 0.3kg/m3 on the lightweight aggregate concrete splitting tensile strength enhanced effect of the highest growth rate of 27%.The flexural strength test shows that the flexural strength of lightweight aggregate concrete can be improved by the incorporation of basalt fiber and polypropylene fiber.The flexural strength increases with the increase of polypropylene fiber and basalt fiber content.Effect comparison of two kinds of fibers on the mechanical properties of lightweight aggregate concrete,found that polypropylene fiber on the compressive strength and flexural strength increase effect is not obvious,and the compressive strength of basalt fiber can slightly improve the lightweight aggregate concrete,can significantly improve the splitting tensile strength and flexural properties.Finally,it is concluded that the optimum fiber content of basalt fiber is 3kg/m3.In the energy saving design,the energy saving effect of fiber lightweight aggregate concrete wall panels can meet the specification requirements.